Subject: [COSE] FW: New Version Notification for draft-mattsson-cose-cbor-cert-compress-00.txt

From: John Mattsson <[email-masked]>
Date: Thu, 12 Mar 2020 07:30:03 +0000

Hi,

We have submitted a new draft to COSE https://tools.ietf.org/html/draft-mattsson-cose-cbor-cert-compress-00. The draft register a new header attribute 'CBORchain' similar to x5chain to signal the conveyed X.509 certificate is compressed with CBOR.

The draft uses https://tools.ietf.org/html/draft-raza-ace-cbor-certificates-04 to compress RFC 7925 profiles certificates by encoding them from DER to CBOR. The aim is to be compatible with all RFC 7925 profiled certificates. With the included example DER encoded RFC 7925 certificate to certificate is compressed from 314 to 136 bytes, a compression rate of 57%.

General purpose compression algorithms (without dictionary) seems not able to compress RFC 7925 profiles certificates. zlib compressed the example 9%, but other certificates and compression algorithms we tested did in many cases increase the size.

We have submitted a similar draft to the TLS WG registering a new algorithms for the TLS 1.3 certificate compression extension.

https://tools.ietf.org/html/draft-mattsson-tls-cbor-cert-compress-00

Cheers,
John

-----Original Message-----
From: "[email-masked]" <[email-masked]>
Date: Monday, 9 March 2020 at 21:21
To: Joel Hoglund <[email-masked]>, Göran Selander <[email-masked]>, Joel Höglund <[email-masked]>, John Mattsson <[email-masked]>, Göran Selander <[email-masked]>, Shahid Raza <[email-masked]>, John Mattsson <[email-masked]>, Martin Furuhed <[email-masked]>
Subject: New Version Notification for draft-mattsson-cose-cbor-cert-compress-00.txt

    A new version of I-D, draft-mattsson-cose-cbor-cert-compress-00.txt
    has been successfully submitted by John Preuss Mattsson and posted to the
    IETF repository.
    
    Name:		draft-mattsson-cose-cbor-cert-compress
    Revision:	00
    Title:		CBOR Object Signing and Encryption (COSE): Headers for Carrying CBOR Compressed Certificates
    Document date:	2020-03-09
    Group:		Individual Submission
    Pages:		6
    URL:            https://www.ietf.org/internet-drafts/draft-mattsson-cose-cbor-cert-compress-00.txt
    Status:         https://datatracker.ietf.org/doc/draft-mattsson-cose-cbor-cert-compress/
    Htmlized:       https://tools.ietf.org/html/draft-mattsson-cose-cbor-cert-compress-00
    Htmlized:       https://datatracker.ietf.org/doc/html/draft-mattsson-cose-cbor-cert-compress

    Abstract:
       Certificate chains often take up the majority of the bytes
       transmitted in COSE message that carry certificates.  Large messages
       can cause problems, particularly in constrained IoT environments.
       RFC 7925 defines a certificate profile for constrained IoT.  General
       purpose compression algorithms can in many cases not compress RFC
       7925 profiled certificates at all.  By using the fact that the
       certificates are profiled, the CBOR certificate compression
       algorithms can in many cases compress RFC 7925 profiled certificates
       with over 50%. This document specifies the CBOR certificate
       compression algorithm for use with COSE.

    
    Please note that it may take a couple of minutes from the time of submission
    until the htmlized version and diff are available at tools.ietf.org.
    
    The IETF Secretariat